DONT GET ANY OF THOSE CARDS!
ok, for under 150 bucks. the 9600 gt or 9600 gso. If your lucky you might find a 8800 gt for cheap. but do not get the above cards.
evga, bfg, and xfx are good brands. sorry but if you want an ati card, the only viable option is a 4850 which, with rebate, can be found for 170~. that card would best my other suggestions but might be out of budget.
i have nothing aagainst ati, they are doing great now. but the last generation of cards weren't very good. the 2600 is all but worthless if you want to game. the 9600 would be a good card for you unless you want to splurge and get the new 4850, which is a very good card.
I definitely agree with the other replies that the ATI 4850 is the best price/performance out there right now. It does run a little warm and can be a bit noisy (neither of which would bother me, but thats MY opinion).
I wouldn't bother with the air duct. I bought the case for my wife, and used the air duct. It restricts air flow in the case causing the ambient temperature in the case to rise. Your better off just leaving it out.
If you wait a few days, Cleeve's article comparing video cards, The Best Gaming Video Cards for the Money will be updated for July. I suspect he will recommend the HD4850, but then considering noise, you may want to wait for the next batch of cards to be released. The current ones use stock coolers, and the next lot will probably include better and quieter coolers.
NOTE: All of these cards are reference design, so no 1 card is going to be faster than the others, factors in choosing are price, combo (if any), and the manufacturing company's rating for customer service.
GIGABYTE GV-R485-512H-B Radeon HD 4850 512MB $194.99
Gigabyte make solid cards, and are a reputable company. No mail in rebate, but discounted initial price ($194.99 vs. $199.99). Free shipping. Combo savings with AMD CPU.
MSI R4850-T2D512 Radeon HD 4850 512MB $199.99 ($174.99 after $25.00 Mail-In Rebate) Free shipping.
MSI is another reputable company, solid card w/ decent rebate. Free shipping. Combo with free game.